1. Technical Field
The disclosed embodiments relate in general to a 3D image based alignment method, and more particularly to an alignment method applied to the barrier-type 3D display, for accurately aligning a barrier and a display panel of the 3D display.
2. Description of the Related Art
Autostereoscopic displays, also known as “Naked eye 3D display”, are able to provide binocular depth perception without the hindrance of specialized headgear or filter/shutter glasses.
Naked eye 3D displays have been demonstrated using a range of optical elements in combination with an LCD including parallax barrier technology and lenticular optic technology to provide stereoscopic vision. Generally, the parallax barrier has optical apertures aligned with columns of LCD pixels, and the lenticular optics has cylindrical lenses aligned with columns of LCD pixels. A parallax barrier could be a sheet with a particular fine trip pattern, or an electro optic panel with fine and vertical stripes (i.e. a display module), alternatively. The parallax barrier is placed at a regular spacing, in front or rear of a colored LCD.
FIG. 1 is a conventional 3D display with parallax barrier in front of display panel. The 3D display 1 includes a backlight system 11, a display panel 13 on the backlight system 11, a parallax barrier 15 above the display panel 13, the polarizers 16a and 16b respectively on two sides of the display panel 13. The parallax barrier 15 having fine opaque stripes separates the light pathway of spatial images into images for left eye and right eye to perceive 3D images. Users can see the left eye image/right eye image while the opaque stripes would block the right eye/left eye in the three-dimensional display mode. If an electro optic panel with fine and vertical stripes (i.e. a display module) is adopted as the parallax barrier 15, the 3D display 1 of FIG. 1 is a 2D/3D switchable display, and the display is in 2D mode when the barrier panel is turned off. Further, a touch sensor could be further integrated into the 3D display 1 by coupling a sensing electrode (not shown) on the parallax barrier 15, to making a 3D display with touch screen.
FIG. 2A-FIG. 2G illustrate a conventional lamination and alignment process of a 3D LCD display. As shown in FIG. 2A, a LCD panel 23 and a 3D barrier module 25 are loaded on a display stage 20a and a barrier stage 20b, respectively. The LCD panel 23 is disposed on a back light 21, and the 3D barrier module 25 is disposed on a clear window 201 of the barrier stage 20b. As shown in FIG. 2B, the camera 26 captures the images of alignment marks respectively on the LCD panel 23 and the 3D barrier module 25, and position of the LCD panel 23 might be adjusted by shifting the display stage 20a according to the image results for pre-aligning the LCD panel 23 and the 3D barrier module 25 positions. An injector 27 drops an UV glue 271 on the 3D barrier module 25, as shown in FIG. 2C. The 3D barrier module 25 is then laminated on the LCD panel 23, as shown in FIG. 2D. Next, a 3D image based alignment is executed by capturing images of 3D screen, as shown in FIG. 2E. Then, as shown in FIG. 2F, the lamination is exposed under an UV light source 29 for curing the UV glue 271, thereby fixing the LCD panel 23 and the 3D barrier module 25 to form a 3D display module. Finally, the barrier stage 20b is unplugged and the 3D display module is ready to be unloaded from the display stage 20a, as shown in FIG. 2G.
No matter what 3D component (i.e. parallax barrier/lenses) is used, the lamination machine of the 3D component and the display panel requires high accuracy and high throughput.